Multiple stage compressor



Oct. 14, 1958 w. H. HOGAN MULTIPLE STAGEVCOMPRESSOR 4 Sheets-Sheet 1 Filed Nov. 2. 1953 ummm FIG. I

Oct. 14, 1958 w. H. HOGAN MULTIPLE STAGE COMPRESSOR Filed Nov. 2. 1953 4 Sheets-Sheet 2 INVENTOR. WALTER H. HOGAN BY A TTOR/VE'Y Oct. 14, 1958 w. H. HOGAN MULTIPLE STAGE COMPRESSOR Filed Nov. 2. 1953 4 Sheets-Sheet 3 FIG. 4

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- INVENTOR. WALTER H. HOGAN BY A TTORWE Y Oct. 14, 1958 w. H. HOGAN MULTIPLE STAGE COMPRESSOR 4 Sheets-Sheet 4 Filed Nov. 2, 1953 FIG. 7

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INVENTOR. WALTER H.HOGAN I BY ATTORNEY United States Patent MULTIPLE STAGE QGMPRESSOR Walter H. Hogan, @lrnsted Falls, Ohio, assignor to Cleveland Pneumatic Industries, Inc, Cleveland, Ohio, a corporation of Ohio Application November 2, 1953, Serial No. 389,705

(Ilaims. (Cl. 230-52) This invention relates to improved air compressors of the multiple stage type and has as its primary object to provide a device of this character wherein all external interconnecting conduits between the several stages have been eliminated, thereby reducing manufacturing costs as well as providing a compact device.

Another object of this invention is to produce a multiple stage compressor constructed and arranged in a manner enabling dead space between the several stages to be reduced to a minimum, thereby greatly increasing volumetric efficiency.

Another object of this invention is to drive such compressor by a compressed air reciprocatory motor of simple and efiicient design, coupled to the compressor to form a single, compact and relatively light unit which can be constructed and operated at low cost.

Another object of this invention is to provide the compressor actuating air motor with automatically actuated fluid controlling means of simple construction assuring efficient and continuous operation of the motor at minimum costs.

Another object of this invention is to utilize the exhaust ing fluid of the compressor motor as a cooling agent for the several stages of the compressor.

A further object of this invention is to provide a compressor simple in construction and automatic in its action, comprising relatively few parts that might get out of order.

Other objects and advantages more or less ancillary to the foregoing reside in the specific construction and aggroupment of the elements peculiar to this structure, as will become apparent from a more complete examination of this specification.

In the drawings, wherein similar reference characters designate corresponding parts throughout the several views:

Figure 1 is a longitudinal sectional view of a compressor embodying the invention.

Figure 2 is an enlarged view of a portion of the lower end of Figure 1, showing some of the parts in different positions.

Figure 3 is a view looking in the direction of the arrows 33 in Figure 1.

Figure 4 is a cross-sectional view taken on the line 4--4 in Figure 1.

Figure 5 is a cross-sectional view taken on the line 5-5 in Figure 1.

Figures 6 and 7 are somewhat diagrammatical views illustrating the fluid conveying and checking means between the several stages of the compressor.

Figures 8 and 9 are views similar to Figures 6 and 7 but illustrating a modified construction.

Referring to the drawings, A generally represents a multiple stage compressor and B a fluid actuated reciprocatory motor for the compressor, which motor includes a housing 10 formed with a cylinder 11 in which is reciprocally mounted a motor piston 12. The lower end of cylinder 11 is closed by a base 13, which is threaded 2,856,116 Patented Oct. 14, 1958 into the housing 10 as at 14, and is provided with fastening bolt receiving lugs 15. A central cylindrical bore 16 extending from the upper end of the cylinder 11 has a cylindrical stem 17 extending therethrough on which is slidably mounted a sleeve valve 18. Stem 17 is fixed to the motor piston 12 by a nut 19 while the valve 18 has its travel on the stem 17 limited by upper and lower caps 20 and 21 respectively.

Near its lower end, sleeve valve 18 is provided with two external longitudinally spaced annular grooves 22 and 23, and near its upper end with two annular locking grooves 24 and 25 adapted to receive a spring pressed locking ball or detent 26, see Figure 2, for momentarily locking or retaining the valve at one or the other end of its stroke. Valve groove 22 is in constant communication With a valve internal annular recess 27 through a radial port 28, while the valve groove 23 has a port 29 leading therefrom longitudinally of the valve and opening in the interior thereof between the upper end of the valve and its recess 27. Formed on the piston stem 17 are three longitudinally spaced annular grooves 30,, 31 and 32, the groove 31 being connected to the lower side of the piston 12 through a stem port 33.

Above the chamber 11, housing 10 is formed of four substantially equally spaced walls 34 which extend radially from the central bore 16. One of the walls 34 is provided with an inlet connection 35, connected to a relatively large annular groove 36 which surrounds the valve 18 by a port 37. Another relatively large groove 38 surrounds the valve 18 above the groove 36, and has an exhaust port 39 extending therefrom.

So far, the description has been limited to the major portion of the air motor actuating the multiple stage compressor about to be described. The motor housing constitutes a supporting base for the compressor which extends upwardly and coaxially therefrom, and as shown includes four stages resulting in four chambers or cylinders 4t 41, 42 and 43 of gradually smaller volumetric capacity. These cylinders are preferably disposed in series or coaxial alignment with the first and largest one 46 adjacent the base or housing 10, and the last and smallest one 43 adjacent the upper end of the compressor. or section 44 fixed to the upper end of the housing 10 by any suitable means such as bolts, not shown. This block is closed by a cap 45 screwed therein as at 46.

Cylinder 41 is formed within a cylindrical member 47 seated in the cap 45 and closed by a cap 48 which is secured to the cap 45 by bolts 49. Cylinder 42 is formed within a section 50, fixed to the cap 48 by bolts, not

shown, while cylinder 43 is formed within a section 51,

also fixed to the section 50 by bolts, not shown. The two last sections are divided by a cross plate 52 screwed in the bottom of section 51. A head 53 has a packed skirt 54 piloted within a counterboreSS formed in the upper end of section 51. This head is fixed to the section 51 by bolts 56, and has a central cylindrical recess 57 having slidable within its lower end an output controlling valve 53, which is normally seated against: the bottom of the counterbore to close the cylinder 43 by a compression spring 59. A threaded connection or outlet port 60 leads outwardly from the cylindrical recess 57. Preferably the compressor sections 48, 50 and 51 are of a cross section substantially as shown in Figure 5, that is, are provided with radially extending peripherally. spaced cooling fins 61. The head 53 is provided with Cylinder 46 is formed within a block member reciprocable therein and rigidly connected to each other in longitudinal spaced relation by spacers 68. Pistons and spacers are held together by any suitable means, such as a through bolt 69.

The upper end of the compression cylinder 4-4) is connected to the inlet port 37 through a passageway 70 and a port 71, the latter being controlled by a one way check valve 72. Exhausting compressed air from the port 39 may be supplied to an annular groove 73 through a port 74, which groove extends around the first section 44, and has a plurality of furrows '75 extending longitudinally therefrom in the form of knurls through which exhausting fluid is free to flow to the cap 48. The upper side of the motor piston 12 as well as the lower side of the com pressor first piston 64 are in constant communication with a vent 76 through a port 77. To prevent admission of foreign matter through the vent '76, it is preferably screened by a felt piece it; retained in position by a tubular plug 79.

Referring to Figures 6 and 7 which diagrammatically show valve constructions in the form embodied in Figure 1, piston 65 slidable in cylinder 41 is shown to carry on its upper face, that is, on the compression side of the piston, a flexible annular valve 84) made of flexible material such as rubber, neoprene or the like. This valve has its inner edge portion fixed to the piston by any suitable means, such as by clamping it between the piston and spacer 68 shown in Figure 1. Extending through the piston are ports 81 located near the outer edge portion of the valve and adapted to be closed thereby. Pistons 66 and 67, while of different sizes, are of a construction identical to that of piston 65, that is, they have ports extending through them adapted to be closed by a resilient annular valve.

The bottom of each cylinder 41, 42 and 43 is also provided with an annular valve 82 made of flexible material such as rubber, neoprene or the like. This valve has its outer edge portion fixed to the bottom wall of its cylinder by any suitable means. The inner edge of this packing is made for close sliding fit with the piston rod formed by the spacers 68, which rod extends through the bottom wall of each cylinder through an orifice 83 of a diameter substantially greater than that of the piston rod.

The operation of the air motor is as follows: Compressed air supplied to the inlet connection 35 from any suitable source, such as an air compressor, is free to flow into the large annular groove 36, and if the parts are positioned as shown in Figure 1, it will flow through the valve port 28 into the valve internal recess 27 and through piston stem port 33 to the underside of the motor piston 12 for driving the piston and its stem 17 upwardly, thereby imparting the first compression stroke to the pistons 64, 65, 66 and 67 by engagement of the upper end of the piston stem with the piston 64. During the upward or working stroke of the motor piston 12, its upper side is vented through port 77 and vent 76 and the sleeve valve 18 is temporarily held in the Figure 1 position by the detent 26 in the valve groove 24. As the piston stem moves upwardly, the upper end of the sleeve valve is first put in communication with the bottom of the compression cylinder 40 through the piston stem groove 32, thereby relieving pressure from the top of the valve through vent port 77 and vent 76. Subsequently the lower end of the valve recess 27 is connected to the lower end of the valve 18 through the piston stem groove 30, thereby admitting pressure fluid on that end of the valve to shift it into the position shown in Figure 2, where it is temporarily retained by the detent 26 in the groove 25.

Pressure fluid from the inlet connection 35 is also admitted into the first stage or cylinder 40 of the compressor through port 71 and passageway 70. As the volumetric capacity of the cylinder 40 is reduced by the upward movement of the piston 64, pressure fluid in that chamber closes the check valve 72 and after having been further compressed by piston 64, flows into the second stage of the compressor in the manner about to be described. As the piston 64 reaches the "end of its upward stroke, the check valve 72 now relieved of the higher pressure from the cylinder 40, again opens passageway 71 to admit pressure fluid to the upper side of the piston 64 via the passageway 70, thereby causing the return or downward stroke of the compressor pistons and motor piston 12 through the piston stroke transmitting member or stem 17.

In the upward position of the valve 18, and before the piston 12 moves downwardly, pressure fluid previously admitted on the lower side of the piston 12, is exhausted through piston stem port 33, valve recess 27, valve port 28, annular groove 38 and exhaust ports 39, 74, annular groove 73 and knurls 75. Also when the valve is in its uppermost position, its port 29 opens into inlet groove 36, and when the piston stern groove 32 reaches the other end of this port, it causes admission of pressure fluid on the upper end of the valve, to shift the valve downwardly and repeat the cycle just described.

Referring now to the operation of the compressor, it will be understood that each upward stroke of the motor piston 12 effects the corresponding strokes of all the pistons 64, 65, 66 and 67, and that the pressure fluid initially admitted into the first cylinder or stage 4-0 and additionally compressed therein, is subsequently recompressed in the other cylinders until it is finally ejected from the last cylinder 43 under pressure much greater than when admitted into first cylinder 40. The flow of compressed fluid from one cylinder to another, takes place during the upward strokes of the pistons through the central orifices 83 provided through the bottom wall of the cylinders 41, 42 and 43, which orifices are normally closed by the inner edge portions of the valves 82. However, as this compressed fluid flows through the orifices as shown by the arrows A in Figure 6, it rises the inner edge portion 01 the valves away from the piston rod 68, thereby opening the orifices to enable a relatively free displacement of compressed fluid from one cylinder to another. Simultaneously the compressed fluid previously admitted on the upper sides of the pistons, is additionally compressed thereby before it is discharged to the next cylinder in the manner above stated. During this additional compression, the flexible valves are subjected to pressure indicated by the arrows B in Figure 6, thereby causing the valves to close the piston ports 81.

During the downward strokes of the compressor pistons, the compressed fluid previously admitted on the undersides of the pistons will exert pressure on the valves 82 as shown by the arrows C in Figure 7, thereby causing the valves to close the central orifices 83. Simultaneously, the compressed fluid will flow through the piston ports 81, as shown by the arrows D in Figure 7, causing the outer edge portion of the flexible valves 80 to lift from the piston to open the ports 81.

As the compressed fluid reaches the last stage or cylinder 43, and its pressure overcomes the force of the spring 59, it will lift the valve 58 from its seat and flow around the valve into the cylindrical recess 57, and therefrom through the connection 60 through a suitable conduit, not shown.

In the modified construction shown in Figures 8 and 9, the packings 182 are the same and operate in the same manner as the packings 82 of Figures 6 and 7, but the pistons, such as 165, instead of being closely fitted within the chamber 141, are spaced from the wall thereof to form an annular passageway 181, which passageway is normally closed by the outer edge portion of a flexible valve carried by the piston and having its inner edge portion fixed thereto. This valve is of a diameter sub stantially equal to that of the cylinder 141, so that during the upward stroke of the piston, pressure exerted thereon as shown by the arrows BB, causes the valve to close the annular passageway 181. During the downward stroke of the piston, the compressed air will flow through the passageway 181 as shown by the arrows DD in Figure 9, causing the outer edge porti an of the flexible valve 180 to lift fro-m the piston to uncover the annular passageway 181.

Although the foregoing description is necessarily of a detailed character, in order to completely set forth the invention, it is to be understood that the specific terminology is not intended to be restrictive or confining and it is to be further understood that various rearrangements of parts and modification of structural detail may be resorted to without departing from the scope and spirit of the invention as herein claimed.

1 claim:

1. The combination with a cylinder and a piston reciprocable therein, of a central orifice through one end wall of said cylinder having a piston rod slidable therethrough, means supplying pressure fluid to said piston through said orifice, and check means preventing escape of pressure fluid through said orifice including an annular flexible element on the inner face of said end wall having its outer edge portion fixed to said cylinder, the inner edge portion of said element normally engaging said rod to close said orifice to pressure fluid tending to escape therethrough but capable of flexing away from said rod to open said orifice by virtue of fluid pressure exerted thereon from said orifice.

2. In a multi-stage compressor, the combination of a plurality of axially aligned partitioned cylinders, pistons therefor connected by a rod slidable through the cylinder partition, a compressed fluid transferring passageway through said partition around said rod, and a flexible annular check valve having one edge portion fixed to said partition and the other extending over said passageway and movable relative thereto to open or close same.

3. In a multi-stage compressor, the combination of a plurality of axially aligned partitioned cylinders, pistons therefor connected by a rod slidable through the cylinder partition, a compressed fluid transferring passageway through said partition around said rod, and a flexible annular check valve having one edge portion fixed to said partition and the other edge portion adapted to flex into and out of engagement with said rod by virtue of fluid pressure differential on said partition and through said passageway to close or open the latter.

4. In a multiple-stage compressor, the combination of a plurality of cylinders in series and rigidly interconnected compressor pistons therefor, with a fluid actuated reciprocatory motor including a motor cylinder and a piston therefor, piston strokes transmitting means between said motor and compressor pistons including a stern for said motor piston, means including a sleeve valve slidable on said stern, means including a port through said stem control ed by said valve for alternately admitting pressure fluid on said motor piston and one of said compressor pistons to effect reciprocatory motion of all of said pistons, check means to retain said pressure fluid on said one compressor piston for first stage compression thereby, and valve controlled means adapted to transfer said pressure fluid under first stage compression to the next cylinder for further compression.

5. In a multiple-stage compressor the combination of a plurality of partitioned cylinders in a series and rigidly interconnected compressor pistons therefor, a fluid actuated reciprocatory motor including a motor cylinder and a piston therefor, piston stroke transmitting means between said motor and compressor piston including a stem for said motor piston, a sleeve valve slidable on said stern, means including a port through said sleeve controlled by said valve for alternately admitting pressure fluid on said motor piston and one of said compressor pistons to effect reciprocatory motion of all of said pistons, check means to retain said pressure fluid on said one compressor piston for first stage compression thereby, and a valve controlled means adapted to transfer said pressure fluid under first stage compression to the next cylinder for further compression, said valve controlled means including a compressed fluid transferring passageway through said partition around said rod and a flexible annular check valve having one edge portion fixedto said partition and the other edge portion adapted to flex into and out of engagement with said rod by virtue of fluid pressure differential on said partition and through said passageway to close or open the latter.

References Cited in the file of this patent UNITED STATES PATENTS 159,533 Westinghouse Feb. 9, 1875 345,673 Chase July 20, 1886 483,172 Schrader Sept. 27, 1892 1,629,495 Frankenberg May 24, 1927 2,231,307 Wallace Feb. 1], 1941 2,339,048 Bixler Jan. 11, 1944 2,374,989 Funk May 1, 1945 2,598,122 Hansen May 27, 1952 2,622,792 Ramclow Dec. 23, 1952 2,633,808 Webber Apr. 7, 1953 2,652,973 Dibble et al. Sept. 22, 1953 2,684,081 Chace July 20, 1954 2,687,845 Young et al. Aug. 31, 1954 2,704,996 Peterson et al. Mar. 29, 1955 

